Vibration Measurements for Membrane Structures by Using Laser Excitation System

The purpose of this study is to establish a measurement method to get vibration characteristics of membrane structures. An impulse hammer or a vibration exciter have been traditionally used to measure the vibration response of constructions and mechanical systems, but this method is not appropriate to apply the impulse force for the membrane structures due to its lightness and flexibility. Consequently, non-contact impulse excitation is applied by using laser excitation system and is absolutely suitable for the vibration measurement of the membrane structures. The proposed method makes the precise measurement of the frequency response in wide frequency range possible because an ideal impulse force is applied to a point on the structure. Moreover, a health monitoring system can be constructed by combining this vibration testing system and damage detection system. Damage of structures can be identified by detecting fluctuations of vibration responses with this health monitoring system.